Striping attachment for knitting machines



Aug. 28, 1934. w SCHUK-NECHT 1,971,581

STRIPING ATTACHMENT FOR KNITTiNG MACHINES Filed May 20.1932 3 Sheets-Sheet l ATTORNEY? Aug. 28, 1934.

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ATTORNEY}- Patented Aug. 28, 1934 sTmPmG ATTACHMENT FOR KNITTING MACHINES Walter Schuknecht, Milwaukee, Wis., assign'or to Phoenix Hosiery Company, Milwaukee, Wis.,

a corporation of Wisconsin Application ,May 20, 1932, Serial No. 612,415

2 Claims. (01. 66-40) This invention relates in general to circular knitting machines and more particularly toan improvement in that type. of knitting machine utilized for knitting stockings or other tubular fabrics having circumferentially extending stripes formed by knitting successive portions with threads of different colors.

With such types of knitting machines heretofore known and used the threads of different colors are successively fed to the knitting mechanism under the control of pivoted yarn fingers.

' The yarn fingers are controlled from a cam drum and at appropriate times are swung to throw the thread into or out of the path of movement of the knitting needles. When a change is to be made from one colored thread to another before one yarn finger is moved to position its thread out of the path of movement of the knitting needles another yarn finger is moved to position its thread in the pathof movement of the needle so that for a time the fabric is knitted of two threads thus forming in the fabric what is known as the lap. Due to the fact that the yarn fingers do not have perfect control over the thread and to the time lag between the operation of the various instrumentalities 'of the machine and possibly for I other reasons, it hasnot been practical with prior knitting machines of this type to control the extent of the so-called lap, that is to say, the extent to which the two threads are incorporated in the fabric when changing over from one stripe to another varies in an uncontrolled fashion with consequent impairment in the appearance of the fabric.

One of the objects of the present invention is to control the extent of the lap in any particular striped stocking or striped tubular fabric to make the lap uniform throughout.

In carrying out the present invention, means is provided for affecting the change from one thread to another not only by shifting the yarn fingers in accordance with previous practice but also by positioning a predetermined number of knitting needles so that their engagement with the threads of the yarn fingers is assured and positioning the remainder of the needles so that they cannot engage the yarns or threads until after these threads have been brought into the control of the knitting mechanism by the predetermined number of needles mentioned.

This peculiarneedleactuation is effected by incorporating in the stitch cam arrangement an additional cam member so disposed and designed as to coact with relatively long butts providedon most of the needles and yet located out of the path of the relatively shortbutts provided on the predetermined number of needles. This auxiliary cam is located so as to form in effect a prolongation of the center cam of the stitch cam arrangement so that as the needles are elevated by the 9 usual cams up to a level where they may. shortly thereafter engage the thread or yarn all except the predetermined number are again lowered before coming to the stitch cam. The predetermined number remain elevated and their engagement with the yarn or thread is insured. After the needles pass the center cam and the'auxiliary cam associated therewith they all come under.the control of the stitch cam which lowers them to form the stitch. During the time that the cylinder 70 is oscillating for the knitting of the heel and toe, the auxiliary cam,-if left in its usual position, would be in the way and break off the needle butts when the cylinder is partially rotated in one direction, that is, moved reversely from its usual direction of movement. To avoid this the auxiliary cam is made shiftable and it is shifted automatically from a cam drum at the appropriate time.

Other objects and advantages reside in cer- 0 tain novel features of the construction, arrangement and combination of parts which will be hereinafter more fully described and particularly pointed out in the appended claims, reference being had to the accompanying drawings, form- 8 ing a part of this specification, and in which:

Figure 1 is a view in vertical section taken on line 1-1 of Figure 2, with parts shown in elevation for the sake of simplicity in illustration;

Figure 2 is a view in horizontal section taken on line 2-2 of Figure 1; Figures 3 and 4 are views in vertical section taken on lines 3-3 and 4-4, respectively, of Figure 1, parts being omitted and parts being broken awayfor the sake of simplicity in tration;

Figure 5 is a fragmentary view on an enlarged scale and illustrating diagrammatically how the auxiliary cam is related to the needle butts; and

Figure 6 is a detail perspective auxiliary cam.

Referring to the drawings, the numeral 1 designates the rotatable cylinder of the conventional knitting machine of the type equipped with the usual and well known accessoriesto enable it to produce a circumferentially striped tubular fabric or stocking. Knitting'needles 2, 3 and 4 are reciprocated in the usual manner in the slots of the needle cylinder and'areidentical in construction except for the length of their illus- 95 view of the 10 butts, the needles 2, of which a small number are provided, having very short butts 2', the needles 3 having butts 3 of intermediate length and the needles 4 having relatively long butts.-

Any desirable number of needles 2 may be provided. Usually the number is small. In one type of machine usually eight needles 2 are employed. As indicated, however, this number may be varied.

The purpose of the difference in length as between the butts of needles 3 and 4 is a conventional usual one, well known to those skilled in the art and in brief is that the needles with the short butts 3' are provided for use in knitting the toe and heel, at such time the long butt needles 4 being thrown out of action in the usual way.

Surrounding the upper end of the needle cylinder is the usual sinker bed 5 and surmounting the sinker bed is a carrier or latch ring 6 supported in the usual way on a bracket 7 carried by a stationary part or by the frame of the machine.

The yarn or threads designated at T and T are moved into the path of the needles or out of such path under theinfiuence of the conventional yarn fingers 10 and 11. The fingers 10 and 11 are pivotally mounted as at 12 on an extension 13 of the carrier 6 and are biased to a position wherein they dispose their threads in the path of movement of the needles by springs 13. The usual cam drum controlled means is provided for shifting the yarn fingers to the position wherein they dispose their threads out of the path of movement of the needles and consists of a lever 14 for each yarn finger, the levers being pivotally mounted as at 15 on the bracket 7 and each having one end engaging under its yarn finger. The opposite end of each lever connects by a wire 16 with a lever 17 pivotally mounted as at 18 and having a downturned end 19 cooperable with the cams 20 of a cam drum 21.

Cooperable with the butts of the needles 2, 3 and 4 is a cam arrangement designated generally at C and made up of the usual block supported on the machine in the usual manner and having a conventional center cam 26, right and left wing cams 27 and 28 and guide cam 29. The present invention also proposes the provision of an auxiliary cam 30 which has a cam face 31 formed as a continuation of the right hand cam face of center cam 26.

The auxiliary cam 30 is formed on one end of a bar 32 which issupported for sliding movement in the cam block. A coil spring 33 is utilized for urging the cam 30 to its operative position, one end of the spring being secured to a screw or pin 34 threaded into a fixed part of the cam arrangement and the other end of the spring engaging a similar pin 35 secured to the bar 32. The movement of the cam 30 under the influence of its spring 33 is limited by its engagement with the rear face of the lower portions of the center cam 26. This arrangement disposes the active surface of the auxiliary cam rearwardly of the active surface of the center cam and in such relation to the path of travel of the butts of the knitting needles that the active face of the auxiliary cam will engage the long butts 4 and intermediate butts 3 but will not engage the very short butts 2.

For the purpose of effecting automatic withdrawal of the auxiliary cam to inoperative position during the time the heel and toe are being knitted, a cam drum 40 is provided with a suitable number of cams 41 which are in cooperative relation to a follower lever 42 supported for of the parts may be made rocking movement on a suitable pivot 43 and connected by a link 44 and crank arm 45 to a rock shaft 46. The rock shaft 46 is supported for rocking movement in a sleeve 47 fixed to bracket members 48. The end of the shaft 46 opposite its crank 45 is provided with a second crank 49'which engages a laterally extending pin 50 secured to the bar 32. When the cam drum 40 rotates and the lever 42 rides up on one of the cams 41 the motion of the lever 42 is transmitted to the crank 49 and this crank wiping against the pin 50 retracts the bar 32 and the cam 30. As a consequence, the needles may pass through the cam arrangement C not only from the right to the left, as viewed in Figure 3, but also in a reverse direction.

The machine operates in the conventional manner to knit the stocking except during that phase of the operation when there is a change over from a stripe of one color to the stripe of another. Referring now to Figure 1, and assuming that the stripe made up of the thread T has been completed and that a stripe made up of the thread T is to be formed, then the yarn finger 10 swings downwardly under the influence of the cam drum control to position its threads in the path of travel of the needles 2. As pointed out above, these needles 2 with their short butts are not lowered by the auxiliary cam 30 but remain elevated and consequently their engagement with the thread T as well as with the thread T' is insured. The remaining needles, however, being lowered by the cam 30 will not be effective to engage the thread T until after this thread is drawn down into the knitting zone by the needles 2. The machine is so timed that just after the needles 2 have all engaged the thread T the yarn finger 11 is elevated to dispose the yarn T p out of the knitting zone. This action is continu ous throughout the knitting of the stocking except when knitting the toe and heel. The knitting of the toe and heel is carried out in the conventional manner and hence need not be described in detail.

With a knitting machine embodying the pres ent invention, the knitting of a uniform lap is insured. The number of needles with the short butts 2' is predetermined and only needles with such short butts are effective to knit during the change from one colored thread or one stripe to another. The appearance of the stocking is consequently enhanced.

While I have shown and described one construction embodying the invention, obviously various changes in the size, shape and arrangement without departing from the spirit of the invention or the scope of the subjoined claims.

The invention claimed is:

l 1. A circular knitting machine comprising a needle cylinder provided with long and medium butt needles and with a limited number of short butt needles, feeding mechanism including shiftable yarn fingers for supplying yarn to the needles, a stitch cam mechanism having the usual center cam and right and left wing cams coact-- fingers but spaced from the path or the butts of the short butt needles to allow the latter to remain elevated'as they pass the point at which the yarn is fed to theneedles, said auxiliary cam being supported for shifting movement transversely with respect to the path of movement of all of the needle butts from its operative to an inoperative position wherein it is out of the path of movement of the butts of all of the needles, yieldable means for urging the auxiliary cam to operative position and cam drum controlled means for shifting said auxiliary cam to inoperative position when the heels and toes are knitted.

2. A circular knitting machine comprising a needle cylinder provided with long and medium butt needles and with a limited number of short butt needles, feeding mechanism including shiftable yarn fingers for supplying yarn to the needles, a stitch cam mechanism comprising a cam block having the usual center cam and right and left wing cams coasting with the butts oi. all of the needles to elevate and depress the same at the proper times, a bar slidably mounted on said cam block for movement toward and away from the path of movement of the needles, an auxiliary cam carried by said bar and forming a continuation downwardly of the center cam, at a point inwardly of its inner edge so as to be cooperable with the butts of the long and medium butt needles to depress the same as they approach and pass the point at which yarn is fed to the needles under the influence of the shiftable yarn fingers and yet be spaced from the path of the butts of the short butt needles to allow the latter to remain elevated as they approach and pass the point at which the yarn is fed to the needles, and means for shifting said bar to move said auxiliary cam to operative and inoperative positions.

WALTER SCHUKNECHT. 

